Nios® V/II Embedded Design Suite (EDS)
Support for Embedded Development Tools, Processors (SoCs and Nios® V/II processor), Embedded Development Suites (EDSs), Boot and Configuration, Operating Systems, C and C++
Announcements
FPGA community forums and blogs on community.intel.com are migrating to the new Altera Community and are read-only. For urgent support needs during this transition, please visit the FPGA Design Resources page or contact an Altera Authorized Distributor.
12748 Discussions

nios2 custom instruction

Altera_Forum
Honored Contributor II
‎07-21-2005 06:45 AM
1,063 Views

Hi,  

 

I know that Nios2 provides custom instruction to implement user functionality. I'd like to know how to use custom instructions with more than 2 inputs. I understand that I can use internal register file. Let's say I want to implement a custom instruction with 4 inputs and 2 outputs. Register r2, r3, r5 and r6 are inputs, and Register r1 and r4 are outputs. How can I write the assembly code? Is the following correct? 

 

mov c1, r2 (copy to internal register) 

mov c2, r5 (copy to internal register) 

custom 1, r1, r3, r6 (result is r1 and the other internal register, say c3) 

mov r4, c3 

 

Regards, 

Tim
0 Kudos

Link Copied

0 Replies
Reply

Community support is provided Monday to Friday. Other contact methods are available here.

Intel does not verify all solutions, including but not limited to any file transfers that may appear in this community. Accordingly, Intel disclaims all express and implied warranties, including without limitation, the implied warranties of merchantability, fitness for a particular purpose, and non-infringement, as well as any warranty arising from course of performance, course of dealing, or usage in trade.

For more complete information about compiler optimizations, see our Optimization Notice.